Life of one YETI - Tom Frajer's Axial Yeti build log

[TomFrajer]

Here is short video of steering response of my Yeti - full yupgraded steering to Vanquish aluminium parts and Holmes Hobbies BLS HV500 servo. I'm pretty satisfied with this "thumbsup"

<iframe width="560" height="315" src="https://www.youtube.com/embed/Z2GeTj-Ou7Q" frameborder="0" allowfullscreen></iframe>

 

[TomFrajer]

I look forward to your review on those shocks.

Had few drives with them and they are much better than stock. I also changed oils to higher thickness (40wt front and 30wt back). If you buy also optional springs you have lot of options for experimenting. Now when I have many aluminium upgrades in place, my rig is much havier than stock and Im thinking about changing front springs to stronger ones as it is not able to fully expand under the weight of the body. Will give it a test drive tommorow...

 

[midnight_f150]

Had few drives with them and they are much better than stock. I also changed oils to higher thickness (40wt front and 30wt back). If you buy also optional springs you have lot of options for experimenting. Now when I have many aluminium upgrades in place, my rig is much havier than stock and Im thinking about changing front springs to stronger ones as it is not able to fully expand under the weight of the body. Will give it a test drive tommorow...

Thank you for the update. What's next for this rig? Do you race it or just ran it for fun?

 

[TomFrajer]

Thank you for the update. What's next for this rig? Do you race it or just ran it for fun?

Next upgrades will be some Integy parts (silver transmission + spur gear cover, blck front bulkhead and upper deck brace, front bumper with springs).

After this, I will move on to painting my Baja bug body that I already have on shelf to give some personality to my build. Then i will do some lights and maybe sound module.

I'm looking for some racing in future but right now this is just a fun thing 8)
There are not any U4 race events in Czech Republic. Some are in Hungary and I hope this will change in future. I will show this rig to some folks and hope I will motivate them to do something simillar.

I can attend to some Short Course events here in CZ, so Im also planning to build some nice Trophy Truck body for this rig - will update this thread so stay tuned

 

[TomFrajer]

Skidplate installed. Ready to make some scrathes tommorow. I also swapped MIP to correct position - now, it slipped just right into transmission output shaft without any problems. When dissasembling MIP, I stripped set screw on it - had some hard times to get it out, but it gave up after using blow torch...

YETI What I really like on this skidplate is the low weight it adds. 238 grams. Now I shuld run 3S with this rig to keep up with the weight of upgrades...

Centered pumpkin axle by Vanquish - so sweeeet!

Ready for destruction?

 

[midnight_f150]

I didn't notice you lived in CZ till I read your reply. Two my favorite rifles come from over your way I love my CZ 452 .22LR and 453 17HMR. Do you live close to where CZ builds these sweet little squirrel hunting guns?

 

[TomFrajer]

I didn't notice you lived in CZ till I read your reply. Two my favorite rifles come from over your way I love my CZ 452 .22LR and 453 17HMR. Do you live close to where CZ builds these sweet little squirrel hunting guns?

Great, now I feel like living in the US 8)

Česká Zbrojovka (CZ) have factory 200 miles fom my city (https://goo.gl/maps/vKSpBySoUK22). It is almost on the other side of our small country

I'm glad you like CZ guns. They also make something bigger for bear hunting:
CZ 805 BREN A1/A2 - Assault rifle - Products

Or famous CZ SCORPION:
CZ SKORPION 61 S
CZ SCORPION EVO 3 A1

 

[TomFrajer]

Here comes the destruction! Traxxas Jato rod end on rear titanium link proved to be the weakest part of whole setup. Had rollover on high grip surface (asphalt) in full speed and it broke. Today's runtime approx. 15 minutes

Any ideas on more robust rod ends than Traxxas TRA5525 ???
But still better to break this than someting more expensive...

 

[TomFrajer]

Mounted stock rear shocks into dual shock configuration. Filled them with 30 wt oil too. I also swapped springs on front suspension. Now I have red ones (hardest) there...

 

[jeepgod]

RPM makes rod ends

 

[TomFrajer]

RPM makes rod ends

Thanks, I found them in some local RC store so I ordered long and short RPM rod ends to have some spares.

 

[TomFrajer]

Wont all that lube on the front diff gears just seep out all over the tub?

You were right, it is leaking. This is shot after 1 hour nonstop bashing. No problems during this session except motor overheating and ESC switching down whole thing. Mamba Monster X without fan is cool as expected. Holmes Hobbies Puller XL 3500 is so hot that you can fry eggs on it. Cannot imagine running 3S with it. Letting it cool down while writing this...

UPDATE: No it was not overheated motor, I just finished battery :-D Still noob :-D

 

[TomFrajer]

Grrrrr, again! :-D
Hope I will not run out of traxxas rods until RPM ones arrive...

 

[TomFrajer]

Rear end is little bumpy when passing obstacles (such as holes in the road). Any suggestions? Lighter shock oil? Or thicker one?

UPDATE: Found this. I will study little bit:
http://home.scarlet.be/~be067749/58/bug/print.htm

 

[TomFrajer]

Beware of YETI!

https://youtu.be/AqM8zxjfV1M

 

[TomFrajer]

I was wondering how much faster Yeti is on 3S compared to 2S. Found some guys measuring top speed using GPS. Result was 17.4 mph (28 kmh) on 2S and 26.7 mph (43 kmh). Pretty impressive.

 

[DeviledEggs]

Oops. Told ya! What a mess.

As for your broken rod ends, you need the longer "Currie length" upper links with that axle. Then you can use the shorter "revo" rod ends which are much stronger. Had the same issue when I switched my rear truss.

Oh, and if youre thinking of going 3s... Do it! Just drop a couple teeth on the pinion. Then start breaking even MORE parts. :lol:

 

[TomFrajer]

20 minutes hard bashig in the dusty environement. Finished with broken rod end on servo horn link. Rear stock bevel gear stripped and probably bent currie axle shaft. Oooops

Those plastic rod ends are really weak spots in whole setup. Hope RPM rod ends will hold up better.

UPDATE: bevel gear and pinion is OK. Cause of the rear drive malfunction is unknown! I taken it apart, cleaned and everything seems working.

 

[TomFrajer]

Breaking apart rear end to investigate and to swap to heavy duty gears...

This is what left from silicone grease [emoji13]
This grease is too thin and gets runny under the heavy load. Next time I will try only little bit of very thick teflon grease (another experiment).

First signs of use on the Currie axle [emoji2]
It is amazing how rocks and small particles are accelerated by front wheels brushing surface of the rear axle. This is POWER. On 2S LiPo!

Yeah Racing bearings. Not good. Did not stayed the abuse. Tried to rotate them and all I heard was cracking of the sand. I will buy Fast Eddy bearings...

Wohooo, Vanquish Currie axle shafts bent - no jumping. I did not expected this at all! Will ask for replacement and also buy another set to have some spares. I will try to straighten these up and we will see...

Stock RTR gears. There is some wear, but they are not stripped as I thought. Pretty impressive. Now that is the question - why the hell rear axle was not turning under the throttle? I thought gears were stripped, but apparently that was not the case. I was running on front 2WD for awhile. Rear center drive line (MIP) was spinning under throttle and set screw was fastened to pinion. Maybe it was hexes loosening and sliping out of pins?

The GASKET! Now I see it, hehe [emoji13]
I was unable to install Incision locker because of it!

Rear is taken apart...

New heavy duty bevel gears. On the left is Boom racing, on the right is Axial racing. Will instal Axial to the rear as it looks more solid and is overdriven.

And now the front...

Broken servo rod. This was GPM racing rod that I instaled on place of stock axial part.

Going back to stock for now and hope it will hold up...

Finished for today. I will put everything back together later. Hope I will be able to straighten Currie axle shafts. Any advice on that? Vinch and rubber hammer?

 

[Vedo]

I had the stock rod ends pull out on the steering servo link the first day I had mine out. The kit had some longer rod ends so I put those on and they are holding up well. Just an FYI if you encounter the same problem with your servo link.